Release notes

What's new in this release:

QBzr 0.21 is companion release for bzr 2.4, and compatible with bzr 2.3.
New features in this release:

qdiff window has been reworked and all controls moved to a toolbar, similar to
one in qannotate window. Also qdiff toolbar provides you new functions: text
search within active pane and also knob to ignore whitespace changes (it's
also available as command-line option).

User can configure the tab width and this setting affects qdiff, qannotate and
qcat windows. By default tab width equals to 8 characters, user can set new
default value in bazaar.conf as ``tab_width = N`` (either via qconfig or
editing [DEFAULT] section of bazaar.conf). Also user can set individual tab
width for branches in their branch.conf.

Other changes include major rework of qinfo dialog (show the same information
as CLI ``bzr info`` does), qcommit dialog now remembers state of "Show
non-versioned" knob between runs, and several other improvements and bugfixes
(see full changelog for details).